Sukhumvit Suites is a really nice place. The area around Soi 13 and the apartment is a quiet place, but only 2 minutes walk to Soi 11 with many bars and restaurants. Its near a BTS station too.
The building itself is a bit older, but they do some restaurations all the time. Its a clean, and very fine place. Check in was very easy with the Lobby-counter.
The apartmen was clean and there is everything you need for a stay there. No luxury but functional, even for longer stays.
Washing machine, small balkony for dry clothes, iron no problem too. If necessary there are two laundry shops at the 14th floor ;) TV programs in englisch are available, also some thai programs with option for englisch sound.
The communication with Serge was always very easy and he replied very quick, if i had some questions.
High recomand :) Thanks a lot to you Serge